Midterm results for revision total knee arthroplasty for component malrotation

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Accurate component positioning in total knee arthroplasty (TKA) is critical for successful patient outcomes.
• Malrotation of TKA components can lead to chronic pain, stiffness, and functional deficits.
• Understanding functional outcomes after revision for malrotation versus aseptic loosening is essential for surgical decision-making.

Purpose of the Study:

• To compare the two-year functional outcomes of revision total knee arthroplasty (TKA) for component malrotation versus revision for aseptic loosening.
• To quantify the improvements in patient function following revision surgery for these distinct TKA complications.

Main Methods:

• Retrospective review of total knee arthroplasty (TKA) cases undergoing revision surgery.
• Comparison of functional outcomes (SF-12, WOMAC, KSFS) between a malrotation group (n=24) and an aseptic loosening group (n=57).
• Statistical analysis using Student t-tests and chi-squared or Fisher's tests to compare outcomes.

Main Results:

• Revision TKA for malrotation involved 16 femoral and 17 tibial components, predominantly with internal malrotation.
• Both malrotation and aseptic loosening revision groups showed significant and comparable improvements in functional outcomes from pre- to 24-month postoperative.
• At 24 months, WOMAC function scores were significantly higher in the malrotation group compared to the aseptic loosening group.

Conclusions:

• Revision total knee arthroplasty (TKA) for component malrotation leads to clinically significant functional improvements.
• The magnitude of functional improvement following TKA revision for malrotation is similar to that observed for aseptic loosening.
• Addressing component malrotation through revision surgery is a viable strategy for enhancing patient function after TKA.